Pneumatic spring struts (gas springs) are widely used to either partly or totally counterbalance engine compartment hoods, trunk lids, rear windows and tailgates of vehicles to facilitate opening them and to hold them open. The force outputs of gas springs may vary considerably with ambient temperature changes. That is, at low ambient temperatures the gas spring produces a force that can be significantly lower than the force produced at higher ambient temperatures. To offset this effect a temperature compensating valve (TCV) assembly is assembled into pneumatic spring strut bodies. The TCV assembly separates the gas chamber of the gas spring into two separate pressure chambers. When the valve is closed, the gas spring functions only using an output, or lift force, based on the volume of gas in a main pressure chamber. At colder ambient temperatures the valve opens, allowing the gas spring to operate and provide an output, or lift force, based on the volume of gas in the main pressure chamber and an additional volume contained in a secondary pressure chamber.
In some cases, such as following damage to the vehicle following a crash, the pneumatic spring strut temperatures may become elevated and it is desirable to equalize the gas pressure between the main pressure chamber and the secondary pressure chamber to prevent excessive gas pressure differentials therebetween and also to release the gas pressure from the pneumatic spring strut to prevent an excessive gas pressure differential between the interior of the strut and atmospheric pressure.